/**************************************************
 * dom-drag.js => 10.2001
 * www.youngpup.net
 * http://www.dynamicdrive.com/dynamicindex11/domdrag/
 **************************************************/
// <script language='javascript'>
// 	Drag.init(ID('barra_de _titre_sensible_o_deplacement'), ID('conteneur_deplacé'));
// 	ID('barra_de _titre_sensible_o_deplacement').onDrag = function(x, y) {scrolldiv.style.top=y * (-1) +'px';}
// </script>

var Drag = {
	obj : null,
	init : function(o, oRoot, minX, maxX, minY, maxY, bSwapHorzRef, bSwapVertRef, fXMapper, fYMapper)
	{
		o.onmousedown		= Drag.start;
		o.hmode			= bSwapHorzRef ? false : true ;
		o.vmode			= bSwapVertRef ? false : true ;
		o.root = oRoot && oRoot !== null ? oRoot : o ;
		if (o.hmode  && isNaN(parseInt(o.root.style.left  ))) {o.root.style.left   = '0px';}
		if (o.vmode  && isNaN(parseInt(o.root.style.top   ))) {o.root.style.top    = '0px';}
		if (!o.hmode && isNaN(parseInt(o.root.style.right ))) {o.root.style.right  = '0px';}
		if (!o.vmode && isNaN(parseInt(o.root.style.bottom))) {o.root.style.bottom = '0px';}
		o.minX	= typeof minX != 'undefined' ? minX : null;
		o.minY	= typeof minY != 'undefined' ? minY : null;
		o.maxX	= typeof maxX != 'undefined' ? maxX : null;
		o.maxY	= typeof maxY != 'undefined' ? maxY : null;
		o.xMapper = fXMapper ? fXMapper : null;
		o.yMapper = fYMapper ? fYMapper : null;
		o.root.onDragStart	= new Function();
		o.root.onDragEnd	= new Function();
		o.root.onDrag		= new Function();
	},
	start : function(e)
	{
		Drag.obj = this;
		var o = this;
		e = Drag.fixE(e);
		var y = parseInt(o.vmode ? o.root.style.top  : o.root.style.bottom);
		var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right );
		o.root.onDragStart(x, y);
		o.lastMouseX	= e.clientX;
		o.lastMouseY	= e.clientY;
		if (o.hmode)
		{
			if (o.minX !== null) {o.minMouseX = e.clientX - x + o.minX;}
			if (o.maxX !== null) {o.maxMouseX = o.minMouseX + o.maxX - o.minX;}
		}
		else
		{
			if (o.minX !== null) {o.maxMouseX = -o.minX + e.clientX + x;}
			if (o.maxX !== null) {o.minMouseX = -o.maxX + e.clientX + x;}
		}
		if (o.vmode)
		{
			if (o.minY !== null) {o.minMouseY = e.clientY - y + o.minY;}
			if (o.maxY !== null) {o.maxMouseY = o.minMouseY + o.maxY - o.minY;}
		}
		else
		{
			if (o.minY !== null) {o.maxMouseY = -o.minY + e.clientY + y;}
			if (o.maxY !== null) {o.minMouseY = -o.maxY + e.clientY + y;}
		}
		document.onmousemove	= Drag.drag;
		document.onmouseup	= Drag.end;
		return false;
	},
	drag : function(e)
	{
		e = Drag.fixE(e);
		var o = Drag.obj;
		var ey	= e.clientY;
		var ex	= e.clientX;
		var y = parseInt(o.vmode ? o.root.style.top  : o.root.style.bottom);
		var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right );
		var nx, ny;
		if (o.minX !== null) {ex = o.hmode ? Math.max(ex, o.minMouseX) : Math.min(ex, o.maxMouseX);}
		if (o.maxX !== null) {ex = o.hmode ? Math.min(ex, o.maxMouseX) : Math.max(ex, o.minMouseX);}
		if (o.minY !== null) {ey = o.vmode ? Math.max(ey, o.minMouseY) : Math.min(ey, o.maxMouseY);}
		if (o.maxY !== null) {ey = o.vmode ? Math.min(ey, o.maxMouseY) : Math.max(ey, o.minMouseY);}
		nx = x + ((ex - o.lastMouseX) * (o.hmode ? 1 : -1));
		ny = y + ((ey - o.lastMouseY) * (o.vmode ? 1 : -1));
		if (o.xMapper)		{nx = o.xMapper(y)}
		else if (o.yMapper)	{ny = o.yMapper(x)}
		Drag.obj.root.style[o.hmode ? 'left' : 'right'] = nx + 'px';
		Drag.obj.root.style[o.vmode ? 'top' : 'bottom'] = ny + 'px';
		Drag.obj.lastMouseX	= ex;
		Drag.obj.lastMouseY	= ey;
		Drag.obj.root.onDrag(nx, ny);
		return false;
	},
	end : function()
	{
		document.onmousemove = null;
		document.onmouseup   = null;
		Drag.obj.root.onDragEnd(	parseInt(Drag.obj.root.style[Drag.obj.hmode ? 'left' : 'right']),
									parseInt(Drag.obj.root.style[Drag.obj.vmode ? 'top' : 'bottom']));
		Drag.obj = null;
	},
	fixE : function(e)
	{
		if (typeof e == 'undefined') {e = window.event;}
		if (typeof e.layerX == 'undefined') {e.layerX = e.offsetX;}
		if (typeof e.layerY == 'undefined') {e.layerY = e.offsetY;}
		return e;
	}
};